Iranian negotiators and representatives of world powers began a new round of talks on Iran's nuclear program here Wednesday.
Following is a brief introduction to talks since 2006 between Iran and the six powers -- Britain, China, France, Russia, the United States and Germany.
Nov. 7, 2013 -- Talks resumed in Geneva. The protracted meeting came tantalizingly close to agreement.
Oct. 15-16, 2013 -- Iran proposed a plan as a basis for negotiations but details of the proposal were not revealed.
Sept. 26, 2013 -- Iranian Foreign Minister Mohammad Javad Zarif met foreign ministers of the six countries on the sidelines of the UN General Assembly, describing their talks as "constructive."
June 17, 2013 -- Iran's new President Hassan Rouhani said that his country will try to be more transparent in its nuclear program to build confidence, sending a positive signal to the world.
April 5, 2013 -- Talks resumed in Almaty of Kazakhstan. During the two-day talks, Iran offered the world powers specific proposals for resolving the country's nuclear program. No practical achievement was realized.
March 18, 2013 -- Expert-level nuclear talks were held in Turkey's Istanbul. A revised proposal was discussed, which asks Iran to suspend its enrichment of 20-percent uranium and disable the underground Fordow facility in exchange for limited sanctions relief.
July 3, 2012 -- An early follow-up technical expert-level meeting was held in Istanbul. Again, no decisive progress was made at the talks, but both sides were open for future discussions.
April 14-June 19, 2012 -- Three rounds of talks were held respectively in Istanbul, Baghdad and Moscow.
Jan. 22, 2011 -- A new round of talks was held in Istanbul. The talks again failed to reach any agreement, but both sides left the door open for future negotiations.
Dec. 6, 2010 -- Iran's top nuclear negotiator Saeed Jalili and EU foreign policy chief Catherine Ashton held closed-door meetings in Geneva.
Oct. 1, 2009 -- Iran pledged to "cooperate fully and immediately" with the International Atomic Energy Agency during talks with top envoys from the six world powers in Geneva.
July 19, 2008 -- Jalili and EU's foreign policy chief Javier Solana met in Geneva. Senior diplomats from the six countries also attended the meeting.
June 14, 2008 -- Solana handed Tehran an updated package of incentives proposed by the six countries in exchange for the freezing of Iran's uranium enrichment.
